Prior to machining a workpiece on a lathe machine, the workpiece is required to be centrally aligned with respect to a chuck and/or a turning axis of the lathe machine. This is usually done by mounting the workpiece on the chuck of the lathe machine and then centrally aligning the workpiece with respect to the chuck using suitable tools and/or centering devices.
U.S. Pat. No. 3,052,479 discloses an air pressure actuated apparatus. The air pressure actuated apparatus includes an air pump. The air pressure actuated apparatus includes an air pressure applying means for applying sub-atmospheric pressure and above atmospheric pressure to means for holding and releasing work according to the pressures. The air pressure actuated apparatus also includes a conduit means connecting the pump with the air pressure applying means. The air pressure actuated apparatus further includes a flow control means embodied in the pump manually operable for controlling the direction of flow of air passing through the pump optionally to create sub-atmospheric pressure and above atmospheric pressure in the conduit means and the air pressure applying means.